Improvement in steam-valves



2 Sheets--Sheet 1. GRANT.

Steam-Valve.

PaKented Feb. 23,1875.

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UNTTED STATES PATENT @FFIGE.

JOHN J. GRANT, OF GREENFIELD, MASSACHUSETTS, ASSIGNOR To HIMSELF ANDSOLON L. WILEY, on SAME PLACE.

IMPROVEMENT IN STEAM-VALVES.

Specification forming part of Letters Patent No. 160,182, dated February23, 1875; application filed July 22, 1874.

To all whom it may concern:

Be it known that I, JOHN J. GRANT, of Greenfield, county of Franklin andState of Massachusetts, have invented certain Improvements inSteam-Valves.

The following description, taken in connection with the accompanyingplate of drawings hereinafter referred to, forms a full and exactspecification, wherein are set forth the nature and principles of theinvention, by which the same may be distinguished from others of asimilar class, together with such parts thereof as are claimed as new,and are desired to be secured by Letters Patent of the United States.

My invention relates to that class of valves which are employed foralternating the flow of steam to or from the ends of the cylinder insteam-engines; and the nature thereof consists in certain improvementsin the details of the construction of the same, hereinafter described,whereby the steam is allowed to pass entirely around the slide, and thevalve is perfectly balanced.

In the accompanying drawings, which illustrate my invention and form apart of the specification thereof, Figure 1 is a view of the exterior ofa cylinder and steam-chest fitted with my improved valve. Fig. 2 is anend view, partially in section, illustrating the exterior parts of theslide. Fig. 3 is a vertical longitudinal section. Fig. 6 is a plan ortop view of the slide-jacket, from which the slide has been removed.Fig. 5 is a view of the conical frustum. Fig. 4 is a horizontal sectiontaken through the slide-jacket, illustrating the arrangement ofsteam-ports and exhaust-ohannel.

The slide-jacket B, into which the steam first enters, is provided witha conical frustum, A, in which are cut the openings which communicatewith the passages leading to the cylinder and the exhaust-channel. Theports 0, situated on opposite sides of the frustum, communicate with thepassages c, which open into the upper and lower ends of the cylinder,respectively, while the ports D connect with the exhaust-channel D,through which the steam can escape. These openings 0 and D are coveredby the cylindrical slide B, which is provided with ports I), throughwhich steam is admitted from the slide-jacket and cavities H, soarranged as to embrace the exhaust-passages D and ports 0, communicatingby means of the channel 0 with the cylinder, so as to let the steamescape from the cylinder, while the port on the opposite side is leftopen for the ingress of steam to the cylinder.

For every ascent and descent of the piston in the cylinder acorresponding rotation of the slide is effected by means of apparatusconnected with the moving parts of the engine, and the completesuccessive alternation of the steam is maintained without theexpenditure of more power than is necessary to overcome the friction.

The interior surface of the cylindrical slide and the surface of thefrustum upon which it rubs are made true and smooth, in order that theymay be steam-tight. The slide is so fitted as to leave a spacefor theingress of steam between it and the bottom of the slide-jacket, and isattached to the spindle K by the radial bars L, in such a manner as toallow the steam to pass entirely around it, as is clearly shown in Figs.2 and 3, thereby causing the valve to be perfectly balanced.

The valve-stem K passes through a stuffing-box, S, and cylindricalaperture out in the yoke 0, and receives a reciprocating rotary motionfrom the arm m, which is connected to an eccentric or other suitabledevice on the main shaft. The said valve-stem is fitted with jam-nuts orcollars N to the yoke O, in such a manner as to be verticallyadjustable, so that when the slide becomes worn the jam-nuts can beslackened, and the said slide forced down to its seat, after which thestem may be secured in the desired position by retightenin g the nuts.

Having thus described my invention, I will state what I claim and desireto secure by Letters Patent in the following clause:

The conical frustum arranged within the valve-jacket, and provided withtwo ports,

opening into the cylinder, and two openings In testimony that I claimthe foregoing I connecting with the exhaust-channel, in comhave hereuntoset my hand this 20th day of bination With the cylindrical slide, havingtwo July, 1874.

ports, through which steam is admitted, and JOHN J. GRANT. cavitiesarranged to embrace the exhaust- Witnesses: passages and passagesleading to the cylinder, AUSTIN DE WOLF,

as and for the purposes described. MARK H. FARNSWORTH.

